On the Capacities of Freestanding Vanadium Pentoxide–Carbon Nanotube–Nanocellulose Paper Electrodes for Charge Storage Applications

Abstract

Herein, a one‐step protocol for synthesizing freestanding 20 μm thick cellulose paper electrodes composed of V2O5 ⋅ H2O nanosheets (VOx), carbon nanotubes (CNTs), and Cladophora cellulose (CC) is reported. In 1.0 m Na2SO4, the VOx–CNT–CC electrodes deliver capacities of about 200 and 50 C g−1 at scan rates of 20 and 500 mV s−1, respectively. The obtained capacities are compared with the theoretical capacities and are discussed based on the electrochemical reactions and the mass loadings of the electrodes. It is shown that the capacities are diffusion rate limited and, consequently, depend on the distribution and thickness of the V2O5 ⋅ H2O nanosheets, whereas the long‐term cycling stabilities depend on vanadium species dissolving in the electrolyte. The electrodes feature high mass loadings (2 mg cm−2), good rate performances (25% capacity retention at 500 mV s−1), and capacity retentions of 85% after 8000 cycles. A symmetric VOx–CNT–CC energy storage device with a potential window of about 1 V exhibits a capacity of 40 C g−1 at a scan rate of 2 mV s−1.

Multiwalled Carbon Nanotubes: Matrix Nanostructured Composites as Electrode Materials for Supercapacitors

“…Nowadays, numerous works are devoted to both the synthesis and electrochemical and electrocatalytic properties’ investigation of carbon‐matrix nanostructured composites (NSCs) filled with transition metal oxides and hydroxides (see for instance other studies). [ 1–8 ] These systems attract a lot of attention largely due to the shown promise of creating composite electrode materials for supercapacitors (SCs) with high functional characteristics. [ 9–19 ] Majority of works focuses on the composites obtained from highly porous carbon matrices with highly developed mesoporosity and specific surface area.…”

Review of Battery-type Transition Metal (Cu, Co, and Ni) Oxide Based Electrodes: From Fundamental Science to Fabrication of a Hybrid Supercapacitor Device

“…Jahrman et al showed that the presence of oxygen vacancies in the V 2 O 5 electrode elevates the electrochemical properties multifold times . V 2 O 5 has also been reported in various composite electrodes like VO x -CNT, V 2 O 5 -graphene, V 2 O 5 @Polypyrrole core–shell nanowires, and rod-like V 2 O 5 @RGO . The lower capacitance retention is improved by the composite electrodes .…”